‘Doomsday vault’ receives its largest ever deposit of seeds

The Global Seed Vault, located on the Norwegian Island of Spitsburgen, serves as a safeguard for plant genealogy against climate change. It recently received its largest deposit of seeds, including staple crops and wild plant relatives, from various global institutions. The vault is designed to remain dry and maintainable even during power failures.

Why is the Global Seed Vault constructed 130 meters above sea level?

What measures are taken to ensure the seeds remain dry?